Research Consensus on Polyphenols
The Following are a Selection from the Studies and Analysis Presented at the Recent
Conference Relating to Fruit and Vegetable Polyphenols - The Studies are Published in
the January 2005 issue of The American Journal of Clinical Nutrition
Dietary Polyphenols and Health: Proceedings of the 1st International Conference on
Polyphenols and Health
The Effects of Polyphenols on Humans: A Review of 93 Intervention Studies
For some classes of polyphenols there are now sufficient intervention studies to
indicate the type and extent of effects on humans in vivo (on humans, not in a test
The publishers of the research are from the National Institute of Agronomics Resarch,
Saint-Genes Champanelle, France, and the Nestle Reserch Center, Lausanne, Switzerland.
- The isoflavones genistein and daidzein found in soy have significant beneficial effects on bone heath among postmenopausal women
- Green Tea Catechins increase our antioxidant levels and improve energy metabolism
- Grape Seed OPCs and Resveratrol and other polyphenols from red wine and red grape skins, and the polyphenols in cocoa, cranberry, apple skin, and some similar supplements have strong beneficial effects on the vascular system
- Quercitin found in onions, apple skins, red wine, broccoli, and green tea helps decrease the risk of cancer by decreasing some cancer markers.
Beneficial Effects of Fruit Polyphenols on Aging and Brain Health
Numerous studies have indicated that individuals who consume large amounts of fruits and
vegetables reduce their risk of suffering age related diseases such as Alzheimer's disease.
Research from our laboratory (see below*) suggests that dietary supplements with fruit or
vegetable extracts high in antioxidants such as blueberry or spinach extracts may decrease
the worsening vulnerability to free radicals that occurs with aging.
These improvements may show up as improved mobility and improved cognitive function. Our
research shows that it is not just antioxidant and antiinflammatory activities by these
nutrients but also improved cell signaling (communication between cells that insures the
development of normal-healthy cells) and improved neuronal communication. *The publishing
researchers are from the US Department of Agriculture Human Nutrition Research Center on
Aging at Tufts University, and The Institute of Pathology, Case Western Reserve University.
Polyphenols and the Inhibition of Cancer
Many plant polyphenols have been shown to have cancer preventing activities in the lab.
For example (Green) Tea preparations inhibit tumor formation in a variety of animal models
involving cancers of the skin, lungs, mouth and tongue, esophagus, stomach, liver, pancreas,
small intestine, colon and prostate. In some cancers the tea is protective throughout the
cancer formation cycle of initiation, promotion, and progression (into the cancerous tumor).
Curcumin (Turmeric), Genistein, and Quercetin also have anti-cancer activity. They inhibit
cancer cell growth, the transformation into cancer, and also cause the destruction and death
of cancer cells. They inhibit metastasis, and inhibit the ability of a cancerous tumor to
feed itself. The amounts used in studies are higher than the amounts normally found in foods.
The study was authored by researchers from the Ernest Mario School of Pharmac, Rutgers
Polyphenols and Cardiovascular Protection
Epidemiological studies suggest that higher intake of polyphenols from fruit and vegetables
is associated with a decreased risk of cardiovascular disease. Polyphenols improve the surface
function of blood vessel walls and help regulate platelets decreasing the risk of an abnormal
blood clot. Imrpoving the function of blood vessel wall cells decreases the risk of coronary
artery disease. The positive effect on platelets decreases the abnormal coagulation (blood
clotting) seen in acute coronary syndromes including a heart attack and unstable angina. The
publishers of the research are from Boston University School of Medicine.